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Scenario 2: .NET Application Modernization on AWS - Microsoft Workloads Lens - AWS Well-Architected Framework
CharacteristicsReference architectureConfiguration notes

Scenario 2: .NET Application Modernization on AWS

As organizations seek to modernize their legacy .NET applications, AWS provides a comprehensive platform for transformation. This scenario addresses the journey from traditional monolithic .NET applications to cloud-based architectures, enabling organizations to use modern development practices, improve scalability, and reduce operational costs while maintaining familiarity with Microsoft technologies.

Characteristics

  • Development evolution: Evolution from traditional .NET Framework monoliths to cloud-based .NET Core/6+ microservices, maintaining familiar Microsoft tooling while enabling modern development practices and improved team productivity.

  • Architectural transformation: Shift from tightly-coupled monolithic architectures to loosely-coupled microservices, adopting API-first approaches and enabling independent service scaling and maintenance.

  • Infrastructure modernization: Migration from on-premises Windows servers to container-based deployments on AWS, using infrastructure as code and automated deployment pipelines for improved operational efficiency.

  • Technology stack update: Comprehensive modernization of the technology stack, including runtime (.NET Framework to .NET Core/6+), databases, authentication, storage, and monitoring solutions to align with cloud-based capabilities.

  • Business benefits: Achievement of tangible business outcomes including reduced operational costs, faster deployment cycles, improved scalability, enhanced innovation capabilities, and simplified maintenance processes.

Reference architecture

Reference architecture diagram

This .NET hosting decision guide helps customers choose the best AWS service for their applications based on their specific requirements, whether they need full control, simplified management, or zero infrastructure overhead. This flowchart considers factors such as development team expertise, operational preferences, and application characteristics to recommend the most suitable hosting option on AWS:

  1. Rehost .NET Framework or cross-platform .NET to AWS (Windows or Linux-based)

    • Managed service: AWS Elastic Beanstalk

    • Self-managed: Amazon Elastic Compute Cloud (EC2)

  2. Replatform .NET Framework or cross-platform .NET to AWS (Windows-based)

    • Serverless containers: AWS Fargate with Amazon Elastic Container Service (ECS)

    • AWS containers orchestration: Amazon Elastic Container Service (ECS)

    • Kubernetes orchestration: Amazon Elastic Kubernetes Service (EKS)

  3. Replatform cross-platform .NET to AWS (Linux-based)

    • AWS serverless containers: AWS Fargate with Amazon Elastic Container Service (ECS)

    • Kubernetes serverless containers: AWS Fargate with Amazon Elastic Kubernetes Service (EKS)

    • AWS containers orchestration: Amazon Elastic Container Service (ECS)

    • Kubernetes orchestration: Amazon Elastic Kubernetes Service (EKS)

    • AWS fully-managed containers: AWS App Runner

  4. Refactor cross-platform .NET to AWS (Linux-based)

    • Serverless functions: AWS Lambda

Configuration notes

  • EC2 Windows Server configuration: Best suited for legacy applications requiring full control or specific Windows Server features. Implement across multiple Availability Zones using Auto Scaling groups, configure Systems Manager for automated patching and management, and use Amazon CloudWatch Application Insights for .NET-specific monitoring. Common challenges include licensing optimization and Windows authentication - address through proper instance sizing and Active Directory integration. Security involves network ACLs, security groups, and regular vulnerability assessments.

  • Elastic Beanstalk implementation strategy: A managed service ideal for traditional .NET applications requiring minimal infrastructure management. Best suited for organizations starting their cloud journey. Implement with blue-green deployments for zero-downtime updates, configure enhanced health monitoring, and use environment variables for configuration management. Common challenges include deployment timeouts and Windows updates, which can be addressed through appropriate capacity planning and maintenance windows. Security is managed through security groups and IAM roles.

  • Container services approach (Amazon ECS or Amazon EKS): Recommended for microservices architectures and modern .NET applications. Amazon ECS offers simpler management while Amazon EKS provides broader orchestration capabilities. Implement service mesh for inter-service communication, use AWS Secrets Manager for sensitive data, and configure auto scaling based on application metrics. Key considerations include container image security scanning, network segmentation, and proper task sizing. Troubleshoot using CloudWatch Container Insights and AWS X-Ray.

  • Serverless architecture pattern: Optimal for event-driven workloads and APIs. Lambda with .NET requires careful attention to cold starts and memory allocation. Implement API Gateway with custom authorizers, use Step Functions for complex workflows, and configure dead-letter queues for error handling. Security focuses on IAM roles and API authentication. Monitor execution times and memory usage to optimize cost and performance.